With advances in lighting industry, small and cost-effective compact fluorescent lamps (CFLs) have revolutionized energy-efficient lighting. Designed to replace the less efficient incandescent lamps, most of them fit into light fixtures formerly used for incandescent lamps. CFLs comprise of two parts — a tube folded to fit into the fixture of an incandescent bulb, and a compact electronic ballast in the base of the lamp to regulate the current through the lamp.
An electronic ballast is growing in popularity to be used with CFLs, other fluorescent lamps and high-intensity discharge (HID) lamps to limit the current which would otherwise rise to destructive levels due to the negative resistance characteristic of these devices.
To know more about the design of a CFL electronic ballast, let’s walk through the following reference designs which come along with all the required documentation:-
CFL Ballast for 7W E27 Lamp:
The reference design is a compact 7W 230V lamp built around a CFL driver IC UBA2213AT from NXP. The board is integrated into the base of a covered CFL lamp. The input voltage for the design is 170 Vac to 254 Vac and the lamp voltage is 56V. The feature-rich CFL driver IC includes a current controlled pre-heat, boosting for fast run-up time, proper shutdown at end of life, saturation protection and lamp power control that is independent from mains variations. More on this Reference Design
CFL Ballast for 26W Spiral Lamp:
This reference design describes a low-cost solution to drive CFL and TL lamps in small size ballast applications. The circuit can drive 26W CFL from 220VAC. The design is built around a 8-pin ballast control IC IR2520D from International Rectifier specifically designed for CFL applications that helps to reduce the component count. The IC includes all the necessary features such as preheat, adjustable run frequency to set the lamp’s power, high starting frequency for soft start and avoid lamp flash, protection from low AC line voltage, auto-restart after line brownout and fault protection from open filament conditions. More on this Reference Design
20W Dimmable CFL Ballast:
This reference design is a 20W dimmable CFL ballast intended to replace incandescent lamps in formal dimming systems. The CFL ballast is built around a high performance ballast driver L6574D. The lamp power can be dimmed from below 20 per cent up to 100 per cent (full illumination) by adjusting the triac dimmer which sets the illumination level. This is adjusted by switching the frequency of the driver circuit that corresponds to the illumination level set by the triac dimmer. Compared to the formal CFL solution, this solution saves energy, provides higher reliability and a much longer operating life. More on this Reference Design